Perovskite oxides having proton conductivity exhibit high conductivity in an intermediate temperature range and are a prospective material for solid electrolytes of intermediate temperature fuel cells. In order to sinter a perovskite oxide to form a solid electrolyte, a heat treatment at high temperature is required.
An anode (fuel electrode) of a solid oxide fuel cell contains a Ni component that serves as a catalyst and further contains a solid electrolyte in order to suppress aggregation of particles of the Ni component and adjust thermal expansion coefficient. An anode containing a solid electrolyte and a Ni component is typically formed by mixing a solid electrolyte and nickel oxide and co-sintering the resulting mixture.
Non-Patent Literature 1 describes firing a pellet, which contains NiO and BaZryCe0.8-yY0.2O3-δ, in air at 1450° C. for 5 hours.